Aerodynamic Performance of a 0.27-Scale Model of an AH-64 Helicopter with Baseline and Alternate Rotor Blade Sets
Abstract
Performance of a 0.27-scale rotor model designed for the AH-64 Apache helicopter (alternate rotor) was measured in hover and forward flight compared with an AH-64 baseline rotor model. Thrust, rotor tip Mach number, advance ratio, and ground proximity were varied. In hover, at a nominal thrust coefficient of 0.0064, the alternate rotor used about 6.4% less power than the baseline rotor. The corresponding thrust increase at this representative hover power condition was approximately 4.5%, which represents an equivalent full-scale increase in lift capability of about 660 lb. Comparable results were noted in forward flight, except for the high-thrust, high-speed cases investigated (Advance ratio = 0.30), where the baseline rotor was slightly superior. Reduced performance at the higher thrusts and speeds was probably caused by Reynolds number effects and blade elasticity differences. (edc)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1990
- Accession Number
- ADA224493
Entities
People
- Henry L. Kelley
Organizations
- National Aeronautics and Space Administration